diff --git a/services/core/java/com/android/server/connectivity/Vpn.java b/services/core/java/com/android/server/connectivity/Vpn.java
index 5d31e40..ab2c002 100644
--- a/services/core/java/com/android/server/connectivity/Vpn.java
+++ b/services/core/java/com/android/server/connectivity/Vpn.java
@@ -258,7 +258,8 @@
     public static final int AUTOMATIC_KEEPALIVE_DELAY_SECONDS = 30;
 
     // Default keepalive timeout for carrier config is 5 minutes. Mimic this.
-    private static final int DEFAULT_UDP_PORT_4500_NAT_TIMEOUT_SEC_INT = 5 * 60;
+    @VisibleForTesting
+    static final int DEFAULT_UDP_PORT_4500_NAT_TIMEOUT_SEC_INT = 5 * 60;
 
     // TODO: create separate trackers for each unique VPN to support
     // automated reconnection